You may age faster if your dad smoked during puberty

People whose fathers smoked during puberty seem to age faster than expected, according to research featured at the 2025 European Respiratory Society (ERS) Congress in September.

“Our research group has previously shown that smoking during puberty may harm not only the person who smokes, but also their future children,” said Dr Juan Pablo López-Cervantes from the University of Bergen, who presented the research. “In this new study, we wanted to explore whether parental smoking in puberty may also influence the biological aging of their future children.”

The researchers did this using a well-established measure of biological aging known as epigenetic clocks. As we age, extra molecules accumulate on the DNA in our cells. This does not alter the DNA code, but it does influence how our genes behave. These so-called epigenetic changes are not only a sign of aging, they are also linked to diseases of older age such as cancer and dementia.

The research included a group of 892 people, ranging in chronological age from seven to 50 years and with an average age of 28, who were taking part in the international RHINESSA study and provided blood samples for testing. Their blood samples were analysed for epigenetic changes, then researchers applied three different scores of biological aging. They were also asked a series of questions, including whether they or their parents had ever smoked and at what age.

The researchers found that people whose fathers began smoking during puberty (at age 15 or younger) were around nine months to a year older than their chronological age on average. When researchers took into account whether the people themselves had ever smoked, this gap between biological and chronological age was greater (14 to 15 months).

In people whose fathers began smoking later in life, researchers found only a small increase in biological age. They found no clear pattern in biological aging in people whose mothers smoked before pregnancy.

“This accelerated biological aging is important as it has been linked to a higher risk of diseases such as cancer, arthritis and dementia in previous research,” López-Cervantes said. “Our results suggest that boys who smoke during puberty may be unknowingly creating harm for the children they go on to have.

“This research does not fully explain why smoking in puberty is linked to faster aging, but we think that when fathers start smoking during puberty, it may alter the epigenetic material of their sperm cells, and that these changes may be passed on to the next generation.

“Although this research is still in its early days, we believe our findings are important for young boys who smoke or consume other types of nicotine products. Stronger efforts to prevent tobacco use in adolescence should be a priority for policymakers. Such efforts could benefit not only the current generations but also those in the future.”

Image credit: iStock.com/michaeljung